PHD2 graph - odd dips in DEC

[bendiddley]

Hi All. I've been getting to grips with PHD2 for the first time with my NEQ6, haven't done any imaging yet, have spent all my evenings when I get them trying to calibrate PHD, anyway I have finally managed it, Pheeeww. So here's a screen shot of my graph from this evening's experiment. PHD is all set-up with the default settings bar changing the focal length setting for my 9x50 finder guider and the calibration steps. As you can see it has these dips in the graph where DEC goes off on his merry way. Anyone know what this might be? I'm wondering if it's periodic error, what do you all think?? The ones in this graph are close together,  at other times there are longer gaps between them, doesn't seem to be an exact pattern to it, so perhaps not PE, maybe DEC slop? I haven't tried weighting the mount east heavy yet, would that help?

 

Okay, so a little bit of time has passed now and another dip has occurred (see image below), it's very similar to the other dips (above) but only one of them this time... strange, does this add a clue?

 

[PhotoGav]

Try dropping the "DEC: Agr" down to around 50. Even better, run the Guiding Assistant and see what values it recommends you to use for all the settings. The 'Agr' is Agression, i.e. how dramatically it tries to make adjustments, so with it set to 100 it is going to be shouting at the mount, rather than gently coaxing it back into place!

With any luck that will help make an improvement.

[bendiddley]

On 1/19/2017 at 22:42, PhotoGav said:

Try dropping the "DEC: Agr" down to around 50. Even better, run the Guiding Assistant and see what values it recommends you to use for all the settings. The 'Agr' is Agression, i.e. how dramatically it tries to make adjustments, so with it set to 100 it is going to be shouting at the mount, rather than gently coaxing it back into place!

With any luck that will help make an improvement.

Hi Gav. Just wanted to update you. Your advice worked! Took the scope and mount out last night and made the DEC Agr adjustment to 50 and I didn't get one dip all night, really pleased! I also decided to try taking some subs and I managed 10 minutes with crisp round stars! I noticed that the corrections on RA looked a bit aggressive too so nudged RA Agr down to 30 and all looked fine. Really appreciated your advice mate, it got my over that hurdle. Cheers!